What is Server Migration?
Server migration is the process of transferring a server's data, processes, and configuration to a new target server or cloud instance. Organizations may migrate servers for resource optimization, to reduce maintenance overhead, for enhanced support, and to achieve deeper integration and modernization. The migration process varies depending on the source and target machine architectures and requires careful planning, tools, and testing for a successful server migration.
What are the benefits of server migration?
Organizations undertake server migrations for both operational and strategic reasons.
Update to modern services
Many organizations perform server migrations to move from outdated and often restrictive infrastructure to modern, scalable, and maintainable platforms. In cloud environments, servers are virtualized and referred to as instances.
Integration with other services
Modern server environments typically connect more easily to well-known tools and services. This integration capability enables faster automation, resulting in more streamlined operations.
Lower management overhead
Organizations may perform server and operating system migrations to the cloud to shift the task of maintenance from their IT team to a cloud hosting provider. An internal IT team must handle updates and backups when using on-premises hardware. On cloud infrastructure, the provider’s IT team handles maintenance responsibilities.
Cost reductions
Migrating to cloud instances also allows organizations to change their IT budgeting model. Organizations typically must purchase on-premises server infrastructure as a capital expenditure (CapEx). Cloud services are usually billed on a recurring basis, either monthly, annually, or using a pay-as-you-go model. For many organizations, this budgeting approach offers better cost efficiencies over hardware ownership.
Security hardening
Modern server platforms offer a safety net for customers, incorporating the latest encryption, identity controls, and data security tools to ensure the secure transfer of sensitive data. It is up to the customer to configure their environment, controls, and tooling to suit their unique security requirements.
Better performance
Cloud instances provide faster access to data stored within the same cloud environment. Cloud options also typically offer a wider range of storage and computing resource choices.
Task-specific servers
Having access to a wider range of resources allows you to migrate from general server infrastructure to more task-specific instances. For example, provisioning GPU-enabled instances accommodates artificial intelligence and machine learning workloads.
What are the key steps in a server migration?
Every server migration will look different, but most will include these server migration steps, including proper planning, a structured migration, and post-migration monitoring.
1. Evaluate current servers and configurations
The first step in a successful server migration project is to inventory your existing files, applications, servers, their configurations, and map dependencies. For example, you would inventory the hardware and software infrastructure for a database, including additional third-party user tools and the APIs that connect your database to other systems.
2. Evaluate target systems
Next, you will document the resources you need to set up in your new environment. For example, you must identify the storage volume required for your database and the management tools necessary to support it in its new environment. You will want to evaluate resources for their capacity to accommodate your current workloads, how these resources can scale in the future, and budgeting requirements.
3. Identify migration strategy
Based on these evaluations, you will then be able to choose which of the two main migration strategies will work best:
- Shift then transform
- Transform then shift
A shift-then-transform migration involves migrating your existing server resources as-is to the new server and then updating data and applications. A transform-then-shift migration involves modernizing and validating your resources in place before migration to the new environment.
4. Establish the target environment
You should have a clear picture of how to provision your new server environment once you’ve chosen a migration strategy. If you are migrating to a completely new server or cloud environment, this process typically involves creating user and administrator accounts, configuring the server, and setting up its network.
5. Migration process
Next, you will perform the actual migration, transferring files, applications, and their configurations. This process may take a considerable amount of time, depending on the data volume and the complexity of the applications you need to migrate. Plan downtime accordingly with all stakeholders.
6. Testing
After data migration, thorough testing ensures everything in your new environment works as expected. Your testing might need to include:
- Verifying critical data integrity
- Checking API responses
- Monitoring network traffic flow
- Monitoring server load
- Testing application performance in the new environment
Comparing post-migration operations to your old environment can also reveal hidden problems or inconsistencies.
What are the types of server migrations?
You can take several different approaches to a server migration depending on your specific business case, existing data, existing infrastructure, and available target environments.
- Physical-to-Physical (P2P): A P2P migration involves moving your data and systems from one physical, on-premises server to another.
- Physical-to-Virtual (P2V): You can migrate a physical server into a virtual machine (VM), which allows you to host your server on modern infrastructure without needing to change your underlying applications.
- Virtual-to-Virtual (V2V): This migration moves a VM-hosted server from one virtual environment to another.
- Cloud migration: The term “cloud migration” typically refers to the process of migrating from physical, on-premises infrastructure to cloud infrastructure. They can be full migrations, with everything hosted on cloud instances, or hybrid migrations, where some services remain hosted locally.
Managed vs. unmanaged server migrations
One of the most important decisions to make in your planning phases is whether your internal IT team will conduct the migration on its own. Internal migration management is referred to as an unmanaged migration. The alternative is to employ a managed service team to handle the migration for you.
The correct choice depends on your team’s available resources, technical skills, and your business goals. Each migration path presents trade-offs among control, cost, and convenience.
Levels of control and responsibility
The service provider handles most of the tasks in a managed migration. Typically, that will include:
- Server provisioning and setup
- Testing
- Ongoing monitoring, updating, and enhanced security patching
A managed migration is beneficial if you have limited internal IT resources or want your internal resources to focus on development and strategy, rather than infrastructure.
In contrast, an unmanaged migration gives you full control over every migration detail, as you are responsible for the entire process. This approach can offer more flexibility, but requires internal technical expertise and labor.
Cost considerations
Managed migrations typically have a predictable cost structure and can include options for ongoing support. In managed migrations, a Service Level Agreement (SLA) offers service availability guarantees, and ongoing costs are usually evenly distributed over time. You bear all potential costs during unmanaged migrations.
Application migrations vs. server migrations
An application migration moves an application stack to a new server. Typically, that includes:
- Services
- Configurations
- All dependencies
The goal of performing an application migration is to ensure that the same end-to-end functionality persists on the new server.
In contrast, a server migration moves the contents of one server to another. Organizations with many different servers often perform server migrations one at a time to ensure service continuity.
What are server migration approaches in the cloud?
There are several common strategies for migration to the cloud. These strategies are known as the 7 Rs of migration:
- Retire
- Retain
- Rehost
- Relocate
- Repurchase
- Replatform
- Refactor
1. Retire
Outdated servers that no longer have application dependencies can be retired. The Retire strategy involves decommissioning the existing server after migrating or archiving applications.
Typically, you will retire a server when it is deprecated or no longer in general use. Outdated applications that rely on the server infrastructure may no longer generate sufficient business value, or are no longer supported.
2. Retain
It is possible to retain a server in your current environment while migrating others to the cloud. Typically, you will choose to retain a server when you are not ready for migration or there’s no immediate benefit to moving it.
3. Rehost
The Rehost strategy, also known as the “lift and shift” approach, involves migrating your server from its current environment to the cloud without modifying it or its operating system.
The benefit of rehosting is that you can quickly migrate data and workloads to a cloud-based solution without needing to redesign anything immediately. Organizations carrying out incremental migrations often choose to rehost.
4. Relocate
The “Relocate” strategy moves a larger volume of virtual servers running one or more applications to a comparable environment in the cloud.
Relocating applications preserves your existing configurations and allows applications to remain available during the actual migration process. The relocation process is an effective way to avoid scheduling conflicts as it can be performed during off-peak hours.
5. Repurchase
This strategy is also called “drop and shop.” You may choose to repurchase with a different vendor or operating system (OS) configuration during a cloud migration, when you identify an alternative that will generate more value in your new, migrated cloud environment.
6. Replatform
“Replatforming,” sometimes called “lift, tinker, and shift,” involves moving existing servers to the cloud with only minor optimizations to take advantage of the new platform, such as OS upgrades. This strategy is particularly effective when you want improved performance without completely rebuilding the server or repurchasing another product.
7. Refactor
Refactoring server applications involves extensively updating their underlying design to take full advantage of a cloud-native environment. This strategy works best when you have a strong business demand to scale, accelerate product releases, or significantly reduce costs, but have outdated, server-bound applications.
Refactoring takes more effort than other migration approaches, but it may offer more long-term value. This approach is also sometimes referred to as “re-architecting.”
What is a server migration tool?
Server migration processes are complex, even in the best of cases, and tools exist to facilitate most stages or tasks within a migration project.
Discovery and planning tools
Discovery tools, like AWS Application Discovery Service, help you understand your current environment. For example, they can scan your existing servers and applications to create a comprehensive inventory and identify all dependencies. These tools can also help assess current resource utilization to recommend specific migration paths.
Application and database migration tools
Specific migration tools automate parts of the migration process, such as application and database migration. These tools can help with extracting configurations from your current environment, optimizing server transfers to the cloud, provisioning the cloud environment, or configuring the destination server.
Database software migration tools, like AWS Database Migration Service, are often used to simplify replatforming or rearchitecting processes when you want to optimize your database for the cloud.
Storage integration tools
Hybrid storage tools, like AWS Storage Gateway File Gateway, can be helpful when you plan to maintain both on-premises and cloud environments post-migration. These tools help facilitate communication and transferring data between your two environments.
Data transfer tools
Data transfer tools like AWS DataSync securely move large volumes of data, help prevent data loss, and, when needed, can typically provide compression and encryption for data in transit. These tools can help synchronize changes made during a migration window to ensure a successful data transfer. Some cloud providers also offer physical or offline transfer services when transferring data over a network places an undue burden on your business operations.
How can AWS support your server migration?
AWS offers a large range of services to support and automate your cloud migration and modernization efforts.
AWS Migration Hub delivers a guided end-to-end migration and modernization journey through discovery, assessment, planning, and execution. Migration Hub is the single destination to help you assess your migration needs, define your migration and modernization strategy, and use automation to simplify your transformation.
AWS Migration Hub provides journey templates, server discovery, dependency identification, strategy recommendations, orchestration, dashboarding, collaborative experiences, and prescriptive guidance to help at every step in your server migrations. Migration Hub provides an integrated experience for discovering migration tools suitable for every type of server migration.
Get started with server migration on AWS by creating a free account today.